System and method for monitoring people and/or vehicles in urban environments

ABSTRACT

System which comprises a plurality of devices for acquiring ( 1 ) identifiers of transmitter devices ( 2 ) by means of radio frequency in the 2.4 GHz band, these acquisition devices ( 1 ) being connected to a central management computer ( 3 ) for sending the captured identifiers of the transmitter devices ( 2 ) in form of tags ( 32 ) in order to include the latter in a database ( 31 ). The method comprises the stages of: —acquiring the identifier of the transmitter devices ( 2 ) at particular points; —extracting the exclusive part; —encrypting said exclusive part in a tag ( 32 ); —sending the tag ( 32 ), acquisition point and time ( 33 ) to a database ( 31 ) of a central computer ( 3 ); —comparing the tag ( 32 ) and time ( 33 ) with the previously stored data in the database ( 31 ).

OBJECT OF THE INVENTION

The present invention relates to a system and method for monitoringpersons and/or vehicles in urban environments.

BACKGROUND OF THE INVENTION

Monitoring and controlling the transit of people and/or vehicles inurban environments has currently become an issue of crucial importanceto municipal and urban authorities. This monitoring does not only affectthe transit of automobiles in the streets of a city, at certain pointswhere traffic jams or dense traffic can occur, but also affects thedeployment of traffic agents, cleaning services and other servicesduring the daily life of the city. This also affects the displacement ofpeople in large groupings and events or in their daily travels to theirworkplace.

Up to now, vehicle traffic was monitored practically in a statisticalmanner, using devices to count the vehicles that travel on a streetduring a certain period of time, such as car counter cables in thepavement, radar devices of video-surveillance cameras. After gatheringthe data at different points in the city, a crossed statistical analysisis performed with the position information of the measurement points.However, this information is confusing, as it does not consider thevariation of vehicle flow rates during rush hours or on different daysof the week (vehicles are often counted during one or two days to obtaina sufficient reliability of the sample), and results are obtained at atime that is too late for municipal authorities to make immediate orshort-term decisions.

On another hand, controlling transit of people is more difficult, and isgenerally performed by installing turnstiles in office buildings or byapproximate head counts using video and photographic cameras. However,the results obtained are highly localised and can vary considerablydepending on the time and conditions of the sample.

The Traffic Measurement System (TMS) of the company Intellione is known,which uses the signal from mobile telephones to position people andvehicles in motion. Considering that in modern cities it is common for alarge percentage of people to carry mobile telephones that are turned onduring their daily activities, the communication signal of thistelephone positions the person, whether moving in a vehicle or walking.Thus, the TMS system allows knowing the movement of people using themobile telephony antenna network of the operators present in a city orurban area. This information can be processed in real time and isapparently reliable.

However, it has certain drawbacks. Firstly, the telephones must bepositioned by triangulating antennas, as the coverage of an antenna canbe quite large (up to several kilometers), so that it is harder todetermine whether the location is a given street or an adjacent one.Secondly, the problem also exists that the antennas are positionedaccording to the coverage needs of the telephony service, so that theycannot provide an optimised distribution for studying traffic in aspecific area, and its use is very difficult inside a building or amedium or small-sized installation. Thirdly, there is the problem ofconfidentiality, as the mobile telephone identifiers leave the networkof the telephone operator in order to be processed, so that there is arisk of violating personal privacy.

DESCRIPTION OF THE INVENTION

The system and method for monitoring people and/or vehicles in urbanenvironments object of this invention presents certain technicalcharacteristics meant to allow studying traffic in real time, such as inthe streets of a city or the like or in a large building, in order tooptimise the possible actions on mobility and transportation.

Thus, the system comprises a plurality of devices for acquiringidentifiers of transmitter devices by means of radio frequency in the2.4 GHz band, these acquiring devices being connected to a centralmanagement computer for sending the captured identifiers of thetransmitters in order to include them in a database. This set-up isdesigned to detect the open signal emitted by the communication devicesthat operate in the free-use frequency of 2.4 GHz. Among these devicesare those that use Bluetooth, Wifi, Zigbee and others. In general,devices for connection to local or personal wireless networks, whichemit their MAC identification in this signal, which can be captured dueto their free access when the device is active, as it forms part of theconnection protocol.

The number of active transmitters is guaranteed, given their greatevolution in the market, for example, in 2007 87% of mobile telephonessold already included Bluetooth technology, and its popularity hasincreased by the extensive implementation of hands-free devices inautomobiles.

Each acquiring device comprises a short-range multi-format transducerfor the 2.4 GHz band, at least one transmitting and receiving antenna,one operation and encryption processor, one long-rangetelecommunications device and one power supply.

The transducer and antenna sweep the coverage area and range of theacquiring device in search of active transmitting devices in order toread their identifiers or MAC address. The data of this MAC (mediaaccess control) address includes a part defined by the manufacturer andthe protocol, which are discarded, and a part that defines exclusivelythe transmitting device, encrypted with an asymmetrical encryptionpassword that allows preserving its exclusive identification whileallowing to manage the information in a confidential manner. Onceencrypted, the tag is sent with the acquisition, or capture, time andacquisition point to the central computer.

This central computer comprises a database of already acquired tags withthe acquisition time and geographical position of the correspondingacquiring device, so that when new tags are received they are comparedwith previously stored tags and the monitoring data are obtained, aswill be described further below.

The acquiring device is housed inside a weatherproof casing, allowing itto be installed in any location according to the needs of the area to bemonitored.

Considering the type of transmitting device to which the acquiringdevices connect, the operational range of the transducer is less than 50meters, preferably from 2 to 35 meters. This allows limiting theacquisition operation to the width of a street or avenue, avoiding theacquisition of transmitters of people travelling on adjacent streets, asoccurs when using mobile telephony signals or those with greatercoverage. Moreover, these acquiring devices allow monitoring flow inhallways or accesses in buildings or installations without requiringdifferent turnstiles or counters.

It has been foreseen that in one embodiment the acquiring devicecomprises two transducers, with their corresponding antennas, separatedfrom each other, for example along the street in which this acquiringdevice is installed, thereby allowing to detect the direction of motion,or by the analysis of the signal intensity (RSSI) which is alreadyincorporated in the protocols of these transmitters.

To achieve a greater autonomy of the acquiring devices, the power supplycomprises a photovoltaic panel and batteries, allowing theirinstallation without having to consider the electrical grid supply.

As mentioned above, in the system the tags bear a reference to thelocation where the transmitters were captured. This reference can beobtained manually at the time of installing the acquiring devices, asthey do not move, or by fitting the acquiring device with a positioningdevice such as a global positioning system (GPS) device that allowsautomatic reutilisation in any other acquisition point without set-upproblems.

The telecommunications device comprises preferably an Internetconnection, either by cable or wireless (WiFi), although directconnections such as mobile telephony, or others, are not ruled out.

Thus, the method of operation of the system comprises the followingstages:

-   -   acquiring at particular points the identifiers of the        transmitter devices in the 2.4 GHz band that enter the radius of        action of the acquiring devices installed;    -   extracting at least the exclusive part of the identifier from        the identifier;    -   encrypting said exclusive part of the identifier in a unique        tag;    -   sending the unique tag, the identifier of the acquisition point        and the acquisition time by the acquiring point to a computer        for its incorporation and processing in a database.    -   comparing in the database the tag and corresponding time with        the previously stored data to determine whether the transmitter        device has previously been in a different acquisition point,        thereby calculating the conditions of its motion and traffic        based on the time difference and the distance between the two        acquisition points.

This comparison can be used to obtain results practically in real timeon the motion of the transmitters, and therefore on the people and thevehicles in which they travel. These data can be filtered by speed, sothat a tag moving at a low speed can in principle be a person on foot ora local resident, while a tag moving at a certain speed (for example, 8kilometers per hour) is a still vehicle, while a tag moving at a highspeed is a vehicle moving in fluid traffic. Likewise, a high flow rateof tags past a point implies a high flow of vehicles or people, while alow flow rate of tags past an acquisition point implies low transit, forexample at night. Crossing the tag data with the position map of theacquisition points even allows identifying whether the transitcorresponds to people who work in the area (the tag is generated at agiven acquisition point early in the morning and appears again late inthe afternoon repeatedly during weekdays) or is a resident (the tag isgenerated constantly and randomly during the day).

It has been foreseen that the identification of the device is the publicpart of the MAC address of the device, which can be accessed by anydevice that attempts connection, such as the multi-format transducer, toallow receiving the Bluetooth, WiFi or Zigbee signals.

To ensure that the data of this public part cannot be used fraudulentlyit has been foreseen that the encryption be performed by asymmetricalcryptography, so that the acquiring device have a public code which,when converting the data of the public part to the tag that is sent,ensures privacy, while allowing each transmitter to be identified in aunique manner at all times.

The comparison comprises classifying tags according to the calculatedspeed of travel of the corresponding transmitter device between twoacquisition points. All of these data can be looked up in real time anddisplayed graphically on a map, which can be filtered so that thedifferent municipal services, such as police, cleaning services, worksand others can carry out actions in real time, simply by linking to thecentral computer via the Internet.

DESCRIPTION OF THE FIGURES

To complete the description being made and in order to aid thecomprehension of the characteristics of the invention, the presentdescriptive memory is accompanied by a set of drawings where, forpurposes of illustration only and in a non-limiting sense, the followingis shown:

FIG. 1 shows a block diagram of the system distributed on the map of acity;

FIG. 2 shows a block diagram of an embodiment of the acquiring device;

FIG. 3 shows a block diagram of an embodiment of the database in thecentral computer.

PREFERRED EMBODIMENT OF THE INVENTION

As shown in the aforementioned figures, the system comprises a pluralityof acquiring devices (1) distributed within the urban area to bemonitored to capture the MAC identifiers of the various activecommunication transmitter devices (2) using the 2.4 GHz band, such asdevices fitted with Bluetooth, WiFi or Zigbee that pass through theareas of influence of said acquiring devices (1). These transmitterdevices (2) are mainly personal devices of the people and vehicles intransit, such as mobile telephones, laptop PCs, PDA's, GPS navigatorsand other communication and remote control devices. The variousacquiring devices (1) are connected to a central computer (3) thatreceives the data generated in each one to include them in a database(31), in this case MySQLServer, and generate practical results.

Each acquiring device (1) comprises a short-range multi-formattransducer for the 2.4 GHz band with its corresponding antenna (12),this range being no greater in this case than 50 meters, or less, inorder to cover the width of a street or avenue. This transducer (11) isassociated with an operation processor (13) which separates and encryptsthe identifier of the MAC address captured in a secure tag (32) that issent with time data (33). In turn, the processor (13) is connected via along-range telecommunications device (14) to the central computer (13),in this case the telecommunications device (14) being an Internet cableconnection module. The acquiring device (1) comprises a power supply(15) for the entire electrical system. All these components areprotected within a weatherproof external casing (16) allowing them to beplaced in any outdoor location considered necessary. The said powersupply (15) comprises a photovoltaic panel and batteries that allow afully autonomous operation of the acquiring device (1).

In one embodiment the acquiring device (1) comprises a globalpositioning module (17), or GPS, so that this acquiring device (1) cantransmit the exact position (34) of its location with the tag (32).

Having described the nature of the invention sufficiently, as well as anexample of a preferred embodiment, it is noted for the applicablepurposes that the materials, shape, size and arrangement of the elementsdescribed can be modified provided this does not imply altering theessential characteristics of the invention as claimed below.

The invention claimed is:
 1. A system for monitoring people and/orvehicles by using existing personal portable communication devices, thesystem comprising a central management computer; a plurality ofacquiring devices for acquiring identifiers of transmitter devices byradio frequency in the 2.4 GHz band, which transmitter devices are theexisting personal portable communication devices carried by peopleand/or vehicles primarily for use independent of the system, theacquiring devices being connected to the central management computer forsending the acquired identifiers of the transmitter devices in the formof tags for incorporation in a database; and wherein each acquiringdevice comprises a short-range multi-format transducer in the 2.4 GHzband, at least one transmission and reception antenna, a processor foroperation and encryption, configured for the extraction and encryptionof the exclusive public part of the Medium Access Control (MAC) addressof the transmitter devices as the identifier of the transmitter devicesin an encrypted, unique tag, a long-range telecommunications device andan electrical power source; and wherein the central management computercomprises the database of the encrypted, unique tags with acquisitiontimes and geographical positions of the corresponding acquiring devices.2. The system according to claim 1, wherein the acquiring device ishoused within a weatherproof casing.
 3. The system according to claim 1,wherein the operational range of the transducer is less than 50 meters.4. The system according to claim 1, wherein the acquiring devicecomprises two transducers with their corresponding antennae separatedfrom each other to detect the direction of motion of the transmitterdevice captured.
 5. The system according to claim 1, wherein theacquiring device comprises a global positioning device.
 6. The systemaccording to claim 1, wherein the telecommunications device is anInternet connection.
 7. A method for monitoring transmitter devices ofpeople and/or vehicles by using existing personal portable communicationdevices, the method comprising the steps of using acquiring devices toacquire at certain acquisition points identifiers of the transmitterdevices in the 2.4 GHz band that enter an operational range of theacquiring devices, wherein the transmitter devices are the existingpersonal portable communication devices carried by people and/orvehicles primarily for use independent of the method; extracting andencrypting the exclusive public part of the Medium Access Control (MAC)address of the transmitter devices as the identifier of the transmitterdevices in an encrypted, unique tag; sending the encrypted, unique tag,acquisition point identifier and acquisition time from the acquiringdevice to a central computer for inclusion and processing in a database;comparing in the database the encrypted, unique tag and the acquisitiontime corresponding with previously stored data in order to determinewhether the transmitter device has previously been in anotheracquisition point, thereby calculating conditions of the transmitterdevice's motion and traffic based on time difference and distancebetween the two acquisition points.
 8. The method according to claim 7,wherein the encryption is performed by asymmetrical cryptography.
 9. Themethod according to claim 7, wherein the comparison comprisesclassifying the tags according to the speed of motion calculated for thecorresponding transmitter device between two acquisition points.
 10. Themethod according to claim 7, wherein active transmitting devices aresearched in the operational range of the acquiring device by thetransducer and antenna.
 11. The system according to claim 1, whereinactive transmitting devices are searched in the operational range of theacquiring device by the transducer and antenna.